More than 800 homes uninhabitable after ‘1-in-500-year’ flood in New South Wales, Australia

A slow-moving low-pressure trough, fueled by warm Tasman Sea temperatures and persistent humid onshore winds, caused days of intense rainfall across eastern Australia, resulting in deadly flooding in New South Wales.

More than 10 000 homes have reportedly been damaged by the floods, which began around May 17 and peaked by May 22. Although floodwaters began to recede and conditions improved starting May 24, around 12 000 people remained isolated due to flooded roads.

At least 794 homes in the Mid North Coast region of New South Wales (NSW) were deemed uninhabitable by the State Emergency Services (SES) on May 27.

This followed more than 5 000 damage assessments conducted by the SES after historic floods in NSW that claimed five lives and isolated over 50 000 people.

Dunmore Bridge, Woodville – May 26, 1PM

A 4WD became stranded after attempting to cross the flooded Paterson River.

NSW SES crews inspected the vehicle to ensure no one was inside. Thankfully, no rescue was required. Reminder:

Never enter floodwaters.

by Brad Ryan pic.twitter.com/94ZP1sZC28

— NSW SES (@NSWSES) May 27, 2025

The Insurance Council of Australia classified this event as an insurance catastrophe, with Andrew Gissing, Chief Executive of Natural Hazards Research Australia, describing it as the “biggest on record for the region, and a 1-in-500-year event.”

Although the term “1-in-500-year flood” is often used to describe the rarity of such events, it does not mean the flood occurs only once every 500 years. Instead, it reflects a statistical probability; specifically, a 0.2% chance of such an event happening in any given year.

The SES responded to more than 1 000 calls related to the floods. More than 140 flood warnings were issued for the region, including significant warnings for the Macleay, Hastings, and Manning rivers.

Overnight, a resident in Gladstone who was unable to access medical care due to flood isolation was safely transported by our volunteers across floodwaters to a waiting NSW Ambulance team, and then on to hospital, ensuring they received the help they needed. pic.twitter.com/eEjrQFVOYV

— NSW SES (@NSWSES) May 25, 2025

The event brought record-breaking rainfall to multiple areas. Taree received 427 mm (16.8 inches) of rain over two days, from May 19 to May 21, making it the town’s wettest May on record. The two-day total accounted for approximately one-third of its annual average rainfall.

The previous May record was set in 2001 when the region received 325.4 mm (12.8 inches) of rain for the entire month.

The Manning River at Taree broke an almost 100-year record on May 21 when its level exceeded 6 m (19.7 feet). Reports indicate that Taree also experienced its highest floodwaters in more than 90 years. Some areas in the affected regions reportedly received more than four months’ worth of rain in 24 hours.

Recovery efforts continue in the affected regions, while post-flood assessments are still underway. The number of damaged and destroyed properties is expected to rise as floodwaters recede, allowing authorities better access for evaluation.